Grinding machine



Feb. 5, 1963 Filed May 3, 1960 G. c. JOYCE GRINDING MACHINE Izmir/3a GLOVEE C JOYCE Fig.2

5 Sheets-Sheet J.

NVENTOR ATTORNEY Feb. 5; 1963 Filed May 5, v1960 3 Sheets-Sheet 2 i 62 54 58 xi 57 60 m 50 J 52 h 1 J 4.2 w 35 7 r34 t *L' A .36

INVENTOR GLOVEE C. JOYCE Q TORNEY W.

Feb. 5, 1963 G. c. JOYCE ,0 ,296

GRINDING MACHINE '"Filed may 3, 1960 s Sheets-Sheet 5 //4 Fl 5. 8 INVENTOR /07 620m 0. J0 YCE BY u m z fi United States Patent 6 "ice chusetts Filed May 3, 1960, Ser. No. 26,644 15 Claims. (Cl. 51-165) The invention relates to grinding machines and more particularly to a combined workpiece positioning, supporting and gaging mechanism.

Grinding machines representative of the prior art have incorporated workpiece supporting, gaging, and positioning mechanisms typically installed as individual units or separate units individually attached to one body but not integral therewith so that a relatively large amount of space is required in which to mount them. Such factors inherently limited the best design and increased the cost of the machine. Moreover, these units typically were mounted so that they interfered with the area through which the workpiece could be loaded into the machine most conveniently either manually or automatically, and thus, they caused a hardship in loading and unloading of the workpieces. In addition, the multiple mounting of these units individually also seriously obstructed the view of the operator. Finally, the prior art pertinent to such machines does not include teachings of in-process gages automatically positioned in engagement with a workpiece and thereafter retracted from engagement with a workpiece in coordinated relation to corresponding movements of the workpiece supporting elements during the grinding cycle by means of which the workpiece is finished.

The instant invention contemplates a more convenient simplified arrangement in which one of the steadyrests or work supporting elements incorporates an axial positioning device combined into one manually adjustable and hydraulically operated unit serving also as the actuating mechanism for one steadyrest, and the actuating mechanism for the other steadyrest or work supporting element incorporates a feature whereby both the work gaging mechanism and the other steadyrest element are engaged and disengaged with the workpiece at the same time.

The mechanism is also designed so as to be a compact unit, combining the steadyrest or work supporting elements, work positioning and gaging elements in a minimum amount of space, such as between two shoulders and around a partial cylindrical portion of a workpiece, such as a crankpin of a crankshaft.

It is therefore one object of the invention to provide a combined compact work sensing, supporting, positioning and gaging mechanism for machine tools. Another object is to provide a combined work sensing, steadyrest, axial work positioner and work gaging mechanism which is simple and practical, containing fewer parts and therefore less costly to manufacture. Another object is to provide a combined steadyrest, axial positioner and gage mechanism which occupies less space for mounting and thereby allows for better design of the machine tool, making it easier to load and unload a workpiece. Another object is to enable the operator to View the workpiece more clearly and thereby avoid spoiled work. Another object is to provide a combined mechanism which is automatic and hydraulically operated. A further object is to provide a combined mechanism operable in coordinated relation to the wheel feed mechanism to initiate, interrupt, resume and terminate the grinding cycle of the machine. A further object of the invention is to provide a mechanism which applies a self-aligning gaging mechanism with as little pressure as possible thereby preventing unnecessary wear or abrasions to the gaging head and the surface being worked upon. A still further object of the invention is to provide a combined mechanism that is automatic in 3,076,296 Patented Feb. 5, 1963 operation, eliminating additional coordinated time and effort that otherwise would be required for applying individual units to a workpiece being machined to perform various functions in the requisite sequence.

In the accompanying drawings in which is shown one of the various possible embodiments of the invention,

FIGURE 1 is a side elevation, partially in cross section of the combined steadyrest, axial work positioner and gage mechanism in the retracted position;

FIGURE 2 is a plan view of the combined mechanism;

FIGURE 3; is an end elevation of the mechanism looking from the right hand side of FIGURE 1;

FIGURE 4 is an end elevation of the mechanism looking from the left hand side of FIGURE 1, partly in section showing the hydraulic portion of the steadyrest feeding mechanism;

FIGURE 5 is a sectional view taken approximately on line 5-5 of FIGURE 2, showing the means for rotating the axial positioning portion of the combined mechamsm;

FIGURE 6 is a fragmentary end view of the axial positioning member looking from the right hand side of FIGURE 1 showing the positioning member rotated into engagement with the shoulder of a workpiece;

FIGURE 7 is an end elevation partly in section of one of the work supporting pot chucks; and

FIGURE 8 is a combined diagrammatically illustrated electrical and hydraulic diagram of the operating mechanisms of the machine.

This invention is particularly applicable to crankpin grinding machines such as those disclosed in the prior US. Patents to Stewart S. Mader, #2,723,503 dated November 15, 1955, and to Herbert A. Silven et al. $1 2,780,895 dated Fabruary 12, 1957, to either of which reference may be had for details not disclosed herein.

As shown in FIG. 8 fluid under pressure is supplied from any suitable source such as, for example, by an electrically driven fluid pump 107 drawing fluid through a pipe 108 from a reservoir 110. The fluid pump passes fluid under pressure to a pipe 112 leading to the various hydraulic components of the machine. A relief valve 114 is provided for maintaining the desired operating pressure within the system independent of variations in the demand for hydraulic fluid.

As illustrated in FIG. 8 of the drawings, a base 10 serves as a support for a transversely movable wheel slide 12 and a rotatable wheel spindle 14, journalled in suitable bearings not shown. The wheel spindle 14- supports a grinding wheel 16 rotatably driven by a motor 18, through multiple VPgTOOVQ pulleys 20 and 24 connected by belts 22.

The base 10 also serves as a support for a pair of synchronously rotatable and axially aligned pot chucks 26 for supporting and rotating the opposite ends of a crankshaft or workpiece 28. Each of the pot chucks are identical in construction and therefore only one of them has been illustrated in FIG. 7 of the drawings. The pot chucks 26 are each provided with a half bearing 3% for supporting one of the ends of the crankshaft 28. A rotatable clamping member 32 is fixed on one end of a shaft 34, rotatable within hearings in each of the pot chucks 26. The other end of the shaft 34 is fixed to a lever arm 36, that is pivotally connected by a pin 38 to one end of a link 45!) connected at its other end by a pin 42 to a link 44 pivotally supported on a pin 46 fixed to the pot chuck 25 to form a toggle clamping arrangement.

A roller 48 is rotatably mounted on the pin 42 and is held in engagement with the end surface of a slidably mounted piston 50, by a tension spring 52, one end of which is attached to the link 44 and the other to the pot chuck 26. The piston 56 is biased to an inoperative 3 position by a tension spring 54, one end being fixed to the inside of the piston 5t and the other end to the pot chuck 26.

When it is desired to clamp a crankshaft or workpiece 23 in the pot chucks 26, fluid under pressure is passed simultaneously through a central passage 56 in each of a pair of synchronously rotatable spindles 57 having flanges for supporting the pot chucks 26. Fluid under pressure then passes through a hole disposed within the periphery of an enlarged recess 66 in the pot chuck 26 and thence through a hole 62, which happens to be in alignment with the first mentioned hole as viewed in FIG. 7, into the cylinder chamber 64, moving the piston 56 contacting the roller 48 and thereby expanding the toggle links 4 and 44 causing the shaft 34 and the clamping member 32 to rotate counter-clockwise as viewed in FIG. 7. Thus, concurrent actuation of the clamping members 32 simultaneously clamps a workpiece in the respective pot chucks 26 against the half bearings 39 thereon.

The base it also is a support for a combined mechanism 130 including an axial work positioner, a work supporting steadyrest, and work gaging means, comprising a housing 132 mounted on a sub-base 134 fastened to the base it As illustrated in the drawings, the sub-base 134 is mounted on a slideway 136 on the base lit and maintained in an adjusted position by screws 138. It is desirable, when applying the combined mechanism 130 to machines that grind a crankshaft complete in which different portions or bearings must be traversed longitudinally so as to position the portions or bearings to be ground opposite the grinding wheel, to provide means for retracting the combined mechanism 130 away from the workpiece so that a new portion of the workpiece can be traversed into the position opposite the grinding wheel. Any suitable retracting means such as an hydraulic cylinder may be employed for retracting the combined mechanism 130 on the slideway 136, the locking screws 138 shown in FIG. 3 being eliminated in this case. The retracting means employed may be connected into the hydraulic system for the machine so as to move the combincd mechanism 130 away from and toward the work by either semi-automatic or fully automatic control means between the grinding cycles for finishing successive crankpins. One such arrangement is illustrated schematically in FIG. 8 and its operation is described further below.

The combined mechanism 139 must be precisely positioned opposite the grinding wheel 16 so that the axis of rotation of a symmetrical workpiece axial positioner 140 passes precisely through the mid plane of the grinding wheel 36. For this purpose, adjustable positioning means are provided comprising a micrometer adjusting screw 142 rotatably mounted in a bracket fixed to the sub-base 134. A slideway 144- is also provided in the sub-base 134 for guiding the housin 132 while it is being adjusted relative to the mid plane of the grinding wheel 16. There are screws 14-6 passing through elongated slots in the housing 132 and threaded into the sub-base 134 for clamping the housing 132 in the adjusted position.

The housing 132 supports a normally open limit switch LS actuated by a spring biased lever ZilZ pivoted on a pin 204 fixed to the housing 132. The lever Z62 serves as a feeler for sensing the presence of a workpiece loaded into the pot chucks 26 and for automatically starting a grinding cycle by closing the contacts of limit switch 8L8.

The housing 13 is provided with a pair of centrally spaced bores and 152 housing a pair of shafts 15 i and 156 at one end of the housing 132, and a pair of shafts 158 and let slidably keyed within the bores 15% and 152 at the other end of the housing I132. A pair of rotatable adjusting shafts 16?; and 164 pass through central bores within the shafts 15S and and have threaded end portions screwed into threaded holes at one end of each of the shafts 15d and 156. The adjusting shafts 162 and 1164 have flanged portions 166 engaging .with the lever arm 132.

one end of the shafts 158 and 169 and a retainer ring 168 at the other end for preventing the axial displacement of the adjusting shafts relative to the shafts 158 and 16%. The adjusting shafts 162 and 164- when rotated cause the shafts 154 and 156 to move axially within the bores to move them either closer to or rarther away from the workpiece 28.

The slidable shaft 156 is keyed to prevent its rotation within the housing 132 and has a fiat portion at one end supporting a fixedly mounted upright bracket 176 having a surface engaging a pin 172, fixed to a gage support arm 174 pivotally supported on a pin 176 fixed to the housing 132. A spring 178 interposed between the housing 132 and the gage arm 174 normally acts to move the gage support arm 174 in a counter-clockwise direction as seen in FIG. 1 so as to allow a spring balanced air gaging head 18%, resiliently pivotally supported on arm 174, to engage the portion or bearing being ground when the shaft 156 moves toward the workpiece such as a crankshaft. The pin 72 is held in engagement with the bracket 170 during the movement toward the work by the spring 178 interposed between the housing 132 and the gage support arm 174. When the shaft 156 is caused to be moved away from the workpiece 23, the bracket 170 engaging the pin 17?: moves the gage support arm 1'74 clockwise to disengage the air gaging head 18% from the workpiece being ground.

The air gaging head 18% may be any of the conventional units on the market such as Airlectric gaging units manufactured by the Sheliield Corporation of Dayton, Ohio.

A lever arm 182, also rotatably supported by the pin 176 fixed to the housing 132, has a steadyrest shoe or element 184 fixedly mounted at one end thereof for engaging the adjacent underside portion of the workpiece or bearing being ground. The stcadyrest shoe 18-: is moved into engagement with the work by the axial displacement of the shaft 156 toward the workpiece by the engagement of one end of shaft 156 with a ground head of a pin 186 fastened into an offset portion 188 integral On retraction of the shaft 156 away from the workpiece, the weight of the lever arm 182 causes disengagement of the steadyrest shoe or element 134 from the workpiece and continued engagement of the pin 186 with the end of the shaft 156.

The shaft 154 is mounted to be rotatable as well as slidable within the bore When grinding shouldered pieces such as a crankshaft 28, it is desirable to remove equal amounts of stock from each side of the shoulders of the bearing, a process known in the art as spark splitting. The spark splitter or axial positioner 14% operable with shaft 154- retracted is mounted on the end of the shaft 154 adjacent the worrpiece 28. The shaft 154 is provided with gear teeth around its periphery at its left hand end which are engaged by the teeth of a rack type piston 19% within a cylinder 19?. shown best in FIG. 5, integral with or attached to the housing 132 and operable in the manner described further below. The teeth of the rack piston 19% meshing with the teeth of the shaft 154 not only serve to rotate shaft 154 when piston 19b is displaced with shaft 154 retracted but also act as a key to prevent the shaft from rotation during axial movement of the shaft 154 with piston at rest. The work positioner 149 has a concave end face 193 into which is fixedly mounted a steadyrest shoe or element Ziiti for engagement with the adjacent portion of a workpiece substantially opposite the grinding wheel 16. The positioner is flatted off on its sides adjacent the cammin surfaces 39 and 196 to provide ample clearance when a workpiece is loaded into and rotated by the machine. A recess is also machined in the positioner 146 to provide clearance for the air gaging head Considering next rotary movement of shaft 154, when fluid under pressure is passed into the cylinder 192, the piston causes the shaft 154- and the axial work positioner Mt} attached thereto to rotate therewith. The work posi- 92 mounted thereon.

tioner or spark splitter 140" has symmetrical. camming portions 194 and 196- (FIG. 6) either of which when rotated less than 90 will engage one or the other of the spaced shoulders of a workpiece 28 such as a crankshaft, so as to cause an axial displacement of the workpiece in one direction until the two camming surfaces contact both shouldered surfaces to precisely position the workpiece relative to' the grinding wheel 16 so that equal amounts of stock will be removed from both shouldered surfaces. When it is desired-to axially position a workpiece for a grinding operation, a solenoid S5 is energized to shift a four-way valve V5 to the right against a spring, allowing fluid under pressure to pass from the pipe 112 into the cylinder 1% causing the piston 190 to rotate the shaft 154 and the axial work positioner 140. The axial positioning of a workpiece is performed immediately after a workpiece has been lowered into the pot chucks 26 and before the clamping of the workpiece thereto.

The fluid pressure operated mechanism described above for clamping and unclamping the workpiece such as crankshaft 28 in the pot chucks 26 is controlled by a four-way valve V12 shifted to the right against a spring by a-solenoid S12, shown energized in FIG. 8, allowing fluid under pressure from the pipe 112 to pass to and move and hold a valve V13 to the left, allowing fluid from the cylinders 64 of the pot chucks 26 to exhaust so that the clamps 32 are withdrawn into a position for unolading of a workpiece such as a crankshaft 28. Fluid under pressure also exhausts from a pressure switch IPS whose function is to be hereinafter disclosed. When the solenoid S12 is deenergized allowing the spring to move the valve V12 to the left, fluid under pressure is directed so as to by-pass the valve V13, allowing the spring to bias valve V13 to the right, and to the pressure switch 1P8, closing its contacts, and through pipes 56 into the cylinders 64 to clamp the workpiece such as crankshaft 28. A check valve 124' allows pressure fluid to bypass the valve V13 when a workpiece is clamped and also prevents fluid exhausted from the cylinders 64 from bypassing the valve V13 when the valve V13 is in a right hand position, thus preventing unclamping of the workpiece in theevent of loss of pressure during rotation of the pot chucks 26 and the workpiece 28.

A grinding wheel feeding mechanism is provided for imparting a transverse feeding movement to the wheel slide 12 comprising a feed nut 7G depending from the underside of the wheel slide 12, meshing or engaging with a rotatable feed screw 72. An hydraulically operated mechanism is provided for rapidly moving the wheel slide 12 to and from an operative position, comprising a cylinder '74 which contains a slidable piston 76 connected to one end of a piston rod 78 connected at the other end to the feed screw 72. The grinding wheel feeding mechanism also comprises a cylinder 80 having a piston 82 upon which are cut rack teeth 34 meshing with a gear train 86 which is substantially the same as disclosed in the U.S. patents to Stew-art S. Mader 472,723,503 or Silven et al. #2,780,895 to which reference may be made for details not disclosed herein;

The gear train 8-5 is connected'to the feed screw 72 so as to rotate the screw 72 and thereby impart a continned feeding movement to the wheel slide 12 after the initial feeding movement has been stopped by the bottom ing of the piston 76 in the cylinder 74. The gear train 86 is also connected to impart a rotary movement to a hand wheel 38 which has a cam 90 including a stop surface A pivotally mounted stop lever 94 is mounted on the base 14 and is provided with a bevelled surface for engagement with the cam portion 90 which causes the lever 9'4 to rotate counter-clockwise. When the hand wheel 88 is rotated counter-clockwise the cam portion 90 engages and rotates the lever 94 so as to allow a normally closed limit switch liLS to close and its function will be hereinafter disclosed. The rotation of the hand wheel 88 is terminated when the stop, surface 92 engages the surface on the upper arm of the stop-lever 94 or before it reaches the stop by operation of the Work size gaging means to be hereinafter described. The grinding wheel feeding mechanism also provides a mechanism for controlling the feeding rate during various predetermined portions of the feeding cycle, which will be hereinafter disclosed.

The mechanism for controlling the wheel feeding rate includes a 4-way control valve V6 actuated by a solenoid S6 for controlling the direction of flow of fluid under pressure to and from the cylinders 74 and 8%, as well as control valves V2, V7, and V10 arranged so that control valve V2 regulates the initial wheel feeding movement by controlling the rate of displacement of the piston 76 within the cylinder 74 and so that control valve V7 and control valve Vii? are actuated sequentially to control the subsequent wheel feeding movement by regulating the rate of displacement of the piston 82 within the cylinder 86.

During the initial portion of the feeding cycle, the mechanically actuated control valve V2 permits a relatively rapid approach feed. Then, since it is desirable when grinding the side shoulders of a bearing of a crankshaft 28 to slow down the wheel slide 12 relative to the rapid approach feeding rate, the control valve V2 operates to initiate a relatively slower shoulder feeding rate until the wheel 16 closely approaches the bearing surface between the respective shoulders. Finally, as the piston 76 closely approaches the end of the cylinder 74, the feeding rate is further reduced to cushion the bottoming of the piston 76.

The spring biased spool contained within the control valve V2 is engaged and displaced by an element of an actuating dog bar assembly tilt) adjustably fixed to and movable with the wheel slide 12 as illustrated in FIG. 8 so that the spool of the control valve V2 is displaced upwardly against a biasing spring when the wheel slide 12 is in its fully retracted position. Thus, the fluid discharged from the cylinder 74 is initially directed through the pipe 99 in the side of the cylinder 74 to and through the valve V2 and thence through the unobstructed pipe discharging from the valve V2 to the return side of the hydraulic system. This arrangement produces the initial rapid approach feed. As the actuating dog bar assembly 105) is displaced with the wheel slide 12 relative to the valve V2, the unobstructed discharge pipe from valve V2 is closed off so that the fluid discharged from cylinder 74 is then directed through an adjustable throttle valve 102 set to produce a relatively slower shoulder feed at the desired rate. Finally, as the piston 7-6 approaches the end of the cylinder 74 it closes oif the pipe discharging from the side of the cylinder and thereafter fluid is discharged from the cylinder solely through the pipe 101 connected at the end of cylinder 74 and thence through a different throttle valve 98 set to produce a relatively slower feed which may conveniently correspond to the body feed subsequently used for grinding the bearing surface of the workpiece.

Notwithstanding the fact that fluid under pressure is admitted simultaneously to the upper end of cylinder 74 and to the left hand end of cylinder 30 as illustrated in FIG. 8 when solenoid S6 of the 4-way valve V6 is energized, the initial wheel feeding movement is produced solely by displacement of the piston 76 because the sole noid S7 of control valve V7 is initially energized to displace the spool of valve V7 to the right and thereby preclude the discharge of fluid from the right hand end of cylinder until limit switch 9L8 is opened at the end of the stroke of piston 76 to deenergize solenoid S7.

It is desirable when starting to grind the crankpin or hearing portion to further vary the rate of wheel feed during the final finishing portion ofthe grinding cycle. With the spool of control valve V7 shifted toward the left by a biasing sprin when solenoid S7 is deenergized, the fluid is allowed to exhaust from the right hand end of the cylinder 80 through control valve V10 in which the spool is biased to the left by a spring and thence through an adjustable throttle valve 164 set to produce wheel feed at a predetermined body feeding rate. When solenoid S19 is subsequently energized, the spool of the control valve V10 is shifted to the right against the biasing spring to further reduce the rate of feed of the grinding wheel 3.6 toward the workpiece by directing the flow of exhaust fluid through an adjustable throttle valve 1% connected in series with throttle valve 104 and control valve V7. The wheel feed produced by the displacement of piston 82 in cylinder fill is terminated by energizin solenoid 57 again to close valve V7.

An hydraulic actuating mechanism is provided for moving the steady rest elements lbs and 2% and the air gaging head 18% into and at of engagement with a workpiece. The mechanism comprises a cylinder 2% housing a piston 268 having rack teeth engaging a gear 210 integral with a shaft 212. The shaft 212 has another gear 214 fixedly mounted on it at the other end meshing with a gear are integral with a feed screw shaft 2%, rotatably supported in bearings 22% within the housing 132. The housing 132 has a central bore 22. into which is slidably keyed a shaft 224, having a threaded hole at its left hand end engaging the threaded portion of the feed screw 218. The slidably keyed shaft 224 has an elongated slot 226 substantially mid-way its ends and a pin 228 fixed to it for rotatably supporting a narrow gear segment 23%. The gear segment 23% meshes with the rack teeth of both of the slidably keyed shafts 15S and 16th to function as a pressure equalizing element. The housing also is provided with an elongated opening 232 having an end surface 234 which engages the left hand surface of the gear segment 23d and serves as a stop for the actuating mechanism in the retracted position as shown in FIG. 1. The right hand end of the elongated opening 232. serves as a positive stop calibrated by adjusting shafts 162 and 16 5 with the finish diameter of a ground workpiece.

The four-way control valve V9 when energized by solenoid S9 is moved to the right against a spring, allowing fluid under pressure from the pipe 112 to pass into the cylinder 2% to move the piston and thereby rotate the gears 2E0, 214, 216 and the feed screw shaft 218, thereby causing an axial movement of the shafts operable to move the steadyrest shoes or elements toward the workpiece 28 at a rate controlled by an adjustable throttle valve 2&7. When the solenoid S9 is deenergized, the valve V9 is spring biased to the left so as to pass fluid under pressure to the cylinder 2%, through a check valve 295 moving the piston in the opposite direction into the position shown in FIG. 8 so as to rotate the gears 210, 214, 2 16 and the feed screw 21% and retract the steadyrest shoes and air gaging head 18% until the left hand surface of the gear segment 23% rests against the surface 234 of the housing 132, the mechanism bein adjusted so that the piston 2&8 does not first bottom in the cylinder 2%.

An angular work positioning mechanism for stopping the pot chucks 26 in a precise angular position is provided for easy loading and unloading of a workpiece either manually or by any well known automatic work handling mechanisms. The angular work positioning mechanism riefly comprises a pair of rotatable notched discs 115 and 116 coupled into the work drive mechanism, a pair of levers having rollers rotatably fixed to them engaging the periphery of the discs 115 and 116 for actuating the limit switches KGLS and 12LS, and a braking circuit of a short duration applied to the windings of the work drive motor 118. The braking circuit is of the type well known in the art. The braking circuit is momentarily applied to the work drive mechanism when work drive motor 113 is deenergized so that the auxiliary drive motor 129 may operate shortly thereafter to precisely position the pot chucks 26 angularly. The auxiliary drive motor 120 is an hydraulic motor coupled into the work drive so as to rotate the pot chucks at a reduced rate so that one of the above said rollers will drop into the notch in the discs 115 to function in the manner which will be hereinafter described. The angular positioning mechanism above described is substantially the same as that disclosed in a prior US. patent to H. A. Silven et al. #2,780,895 to which reference may be had for details not disclosed herein.

A control valve V11 moved to the right against a spring by a solenoid S11 is provided for directing the flow of fluid to the hydraulic motor 120, operable at a relatively slow rate controlled by an adjustable throttle valve 122, to rotate the pot chucks 2d and discs and until the roller contacting the disc 115 drops into the notch for a precise positioning of the pot chucks 26.

The operation of the machine will now be described. With the machine in the condition shown in FIG. 8, that is with the switch SW1 closed supplying power to the different electrical components, a relay 23GB. is immediately energized through the normally closed contacts of a relay TEECR and through the normally open contacts, now closed, of a limit switch 12LS. The closing of the normally open contacts of the relay 23CR energizes a solenoid S12 through the normally closed contacts of a relay IECR, shifting the valve V12 to the right. The switch SW2 is closed also and the electrically driven hydraulic pump 10? supplies fluid under pressure into the pipe 112 and thence to the various hydraulic elements of the machine. A switch SW3 is closed also so that the grinding cycle will automatically start when a workpiece such as a crankshaft is deposited into the pot chucks 26. Alternatively, if it is desired to manually operate the machine, the switch SW2 is left open until after a workpiece has been deposited into the pot chucks 26 closing the limit switch 81.3 and then the rinding cycle may be started by closing the switch SW3. Finally, with switch SW4- closed, the grinding wheel drive motor 18 is energized.

A crankshaft 28 is lowered into the machine either manually or by an automatic loading and unloading mechanism, as diagrammatically represented in FIG. 8 by a crank shaft 28 shown supported by hooks 24th which represent the work engaging portion of any one of such mechanisms known to the art, such as that disclosed in a US. Patent No. 2,813,380 to Joseph W. Narel et al. issued November 19, 1957, to which reference may be had for details not disclosed herein. When the crankshaft is lowered into the pot chucks 26 the portion to be ground contacts the end of the sensing lever 202, rotating it clockwise so as to close the normally open contacts of the limit switch SLS. Closing of the contacts of the limit switch 8L8 energizes a time delay relay STR, closing one set of its contacts instantly on energization, the other set being timed on energization to open after a predetermined time interval has elapsed. Closing of the normally open contacts or" the relay STR energizes a solenoid S5 through a normally closed manually operable switch SW5 and also energizes a relay lTR. The solenoid 55 moves the valve V5 to the right allowing fluid pressure from the pipe 112 into the cylinder 192 to rotate the axial positioner mechanism 149 and thereby axially position the workpiece 28. The energization of the time delay relay lTR closes one set of its contacts instantly which is connected in series with another set of its own contacts that is timed to close after a short interval at which time the relay R is energized, opening its normally closed contacts breaking a circuit to deenergize the solenoid S12".

Deenergization of the solenoid S12 allows spring pressure to move the valve V12 to the left, allowing oil under pressure to pass through the passages 56 into the cylinders 64 of the pot chucks 2d clamping the workpiece 28 in the pot chucks 26. At the same time fluid under pressure closes a pressure switch 1P8 closing its contacts and thereby energizing a relay MCR. Energization of the relay MGR opens a set of normally closed contacts and closes a normally open set of contacts. The opening of the normally closed set of contacts dcenergizes the solenoid S5 allowing the valve V5 to move to the left acrea e 9 under spring pressure, thus permitting fluid under pressure to pass to the opposite end of the cylinder 192 to return piston 1% and thereby rotate the axial work positioner Mt) to an inoperative position, shown best in dashed lines in FIG. 6, out of engagement with the shouldered portions of the workpiece 28. Closing of the normally open contacts of the relay 146R energizes the solenoid S6 through the normally closed contacts SZCR of the gaging mechanism including the gage head 1% and the solenoid S7 through the normally closed limit switch 9L8, shifting the valves V6 and ,V7 to the right allowing oil under pressure to enter the cylinder 74 moving the piston 76 land the wheel slide 12 forward, and also applying fluid under pressure to the feed cylinder 80 arranged on rotate the feed screw 72 and the hand wheel 38. However, the piston 82 is not immediately displaced relative to cylinder 80 for reasons which will become apparent below.

When the wheel slide moves forward, a normally closed limit switch lLS closes its contacts energizing a relay I'TCR. Closing of the two sets of normally open contacts of the relay 170R energize-s a relay 180151 and a time delay relay ZTR through a normally closed limit switch lilLS and also energizes the solenoid S8. The normally closed contacts of the relay 180R open to break the braking circuit to the work drive motor 118 and also de energizes the relay 23CR, opening its contacts to prevent the solenoid S12 from becoming energized. The two sets of normally open contacts of the relay ISCR close, one set starting the work drive motor 113 and the other set by-piassing a set of contacts of the relay 17CR, thereby holding the relay ISCR and the time delay relay ZTR energized independent of 17CR.

Shortly thereafiter the time delay relay STR times out opening its timed contacts to deenergize the time delay relay ITR opening its contacts and thereby deenergizing the relay 13CR so that its normally closed contacts close. Since the relay 236R is now deenergized and its normally open contacts are open, the solenoid S12 cannot now become energized.

The energization of the solenoid Sti moves the angular positioning rollers out of engagement with the notched rotatable discs lid and 116 by moving the lever actuators lJO the right. A limit switch IZLS is released as the rollers move out of engagement with the discs, opening a normally open set of contacts and closing a normally closed set of contacts of the limit switch IZLS.

When the relay ISCR and the time delay relay ZTR are energized, they are held energized through one set of the now closed contacts of the relay 1'7CR and through the normally closed contacts of the limit switch lfiLS. Energizing of the time delay relay ZTR opens its contacts immediately, the contacts being in series with one another and also in series with a set of normally open contacts of a relay ZZCR that now becomes energized when the above said normally closed contacts of the limit switch 1213 close in response to energization of the solenoid S8, thus preventing solenoid S11 from becoming energized, and thereby preventing premature operation of the hydraulic auxiliary drive motor 12o.

With work drive motor 118 energized, the workpiece or crankshaft 28 is now rotating and the wheel slide is moving toward the workpiece. When the grinding wheel reaches the shoulders of the crankpin, a valve VZI has been gradually shifted by spring pressure so that the exhaust oil from wheel slide cylinder 74 has been throttled so as to provide a slower shoulder feeding rate. When the grinding wheel reaches the body portion between the shoulders of the crankpin shortly before the wheel slide piston 76 bottoms, a limit switch 9L8 is actuated by the dog bar loll opening its normally closed contacts, deenergizing the solenoid S7 allowing the valve V7 to shift to the left and oil under pressure to exhaust from the hand wheel feed cylinder 80 at a body feed rate controlled by a throttle valve 1%, so that wheel feed cylinder 80 now becomes operative. The grinding wheel reduces the diameter of the crankpin at a body feed rate determined by throttle valve roe until the cam 9d on the hand wheel 88 rotates the lever 94- counterclockwise allowing the normally closed contacts of the limit switch llLS to close energizing the solenoid 89 which shifts a valve V9 to the right allowing oil under pressure to move into the cylinder 2% to move the piston 2% and thereby move the steadyrest shoes and the air gaging means into engagement with the crankpin or work portion being ground.

Grinding of the workpiece continues until the crankpin has been reduced in size so that the contacts SlCR of the air gaging means close energizing a time delay relay 3TR and a relay ZtlCR. Energizing the relay ZfiCR closes its normally open contacts energizing solenoid S10 and solenoid S7. Since the normally closed contacts of limit switch hLS are now held open, solenoid S7 is energized through the closed contacts of the relay 3TR timed to open a predetermined interval after the coil of relay FsTR is energized. The energiz'ation of the solenoids SM and S7 shifts the valves Vllt] and V7 to the right preventing the exhaust of fluid from the hand wheel feed cylinder 30 causing a period of dwell by stopping the infeed of the grinding wheel, thereby allowing the rounding up of the crankpin or hearing due to spring or stress induced by the grinding pressure against the crankshaft 28. After a short delay the normally closed timed to open contacts of the time delay relay STR, open deencrgizing the solenoid S7 only, leaving the solenoid Slil energized and the valve V10 in the right hand position so that oil is now exhausted through a fine feed throttle valve 106. The grinding of the workpiece continues at a fine feeding rate until the normally closed contacts SZCR of the air gaging means open deenergizing the solenoid 56 allowing the valve V6 to shift to the left to pass fluid under pressure to the opposite sides of the hand wheel feed cylinder it and the wheel slide cylinder 74 to move the grinding wheel slide 12, the grinding wheel to and the hand wheel 88 in the opposite direction to an inoperative position.

When the wheel slide moves rearwardly, limit switch 9L8 is released and the limit switches lLS and lllLS are actuated. The normally closed contacts of the limit switch 9L8 close, energizing the solenoid S7 to move the valve V7 toward the right. The opening of the normally closed contacts of the limit switch lLS deenergizes the relay li'CR opening its contacts, deenergizing the solenoid S8. Opening of the normally closed contacts of the limit switch llLS deenergizes the relay ZGCR, the solenoid S9 and the time delay relay STR closing its normally closed contacts. Deenergization of th erelay ZllCR opens the contacts of the relay ZtlCR, deenergizing the solenoid S10 allowing the valve Vltl to shift toward the left. The deenergized solenoid S9 allows the valve V9 to move to the left under spring pressure, allowing fluid under pressure to pass to the opposite end of the cylinder 2% and retract the steady-rest shoes or elements 134 and 2% and the air gaging means including gage head 18%. When the gage head ltiti is retracted, its normally closed contacts SZCR close and its normally open contacts SlCR open.

When the solenoid S8 is deenergized, the angular positioning rollers are allowed to roll upon the angular work head locating discs M5 and 116 and when one of the spring biased rollers momentarily drops into the notch of the disc 116, the contacts of the limit switch ltlLS are opened momentarily, deenergizing the relay ltlCR. Opening of one set of the normally open contacts of the relay ltiCR breaks the holding circuit through the limit switch liiLS deenergizing the time delay relay ZTR so that the continued rotation of the disc actuating the limit switch ltlLS will not effect a reenergization of the time delay relay ZTR and the opening of the other set of normally open contacts of 186R breaks the circuit of the work drive motor. The closing of the normally closed contacts of lidCR also stops the coasting work drive motor almost instantaneously by applying a momentary braking circuit diagrammatically shown to stop the rotation of the work drive heads. The deenergization of the time delay relay ZTR closes one set of contacts immediately, but the other set is timed to close after a short period of time has elapsed, allowing time for braking of the work drive motor 118. The subsequent closing of the timed contacts of the time delay relay ZTR energizes the solenoid Slfl shifting the valve Vitl to the right allowing oil under pressure to rotate the hydraulic motor 12631 and thereby rotate the work heads and the notched discs 115 and 116 slowly until th second spring biased roller drops into the precise angular locating notch of the disc 115 thereby opening the normally closed contacts of the limit switch EELS, deenergizing the relay ZZCR, opening its contacts which deenergizes the solenoid Sill, allowing the valve Vial to shift toward the left to stop the rotation of the hydraulic motor lid.

At the same time, the normally open contacts of the limit switch llZLS are held closed energizing the relay ZBCR to close its contacts, energizing the solenoid S12, shifting the valve V12 to the right, allowing fluid under pressure to move the sequence valve V1? to the left which allows oil to exhaust from the pot chuck cylinders and from the pressure switch 1P5 which opens to decnergize the relay MCR. The exhaust of pressure fluid from the pot chucks unclamps the workpiece of crankshaft 23, so that the workpiece may be removed therefrom. The opening of the normally open contacts of the relay l-tCR breaks a circuit to the contacts SZCR of the air gaging means so that they will have no effect in the event they a e opened While the air gage is adjusted. The crankshaft or workpiece is then removed and the spring biased lever MP2 rotates counter-clockwise allowing the normally open contacts of the limit switch 8L8 to open, thereby deenergizing the time delay relay TR and resetting the same. When a new crankshaft is deposited in the pot chucks 26, the cycle is again repeated as above described.

The embodiment of the instant invention described above may include a configuration in which the sub-base 13 i is mounted for reciprocation on the slideway 136 by means of a suitably controlled hydraulic cylinder, when such an arrangement is desirable. The showing in KG. 3 includes a schematic representation of one arrangement for this purpose including a manually operated four-way valve V connected to the pipe 112 through a shutoff valve so that valve V15 may be selectively supplied with pressure fluid by appropriate manipulation of valve The four-way valve Vlfi in turn supplies pressure fluid to one end or the other of an actuating cylinder 1 5 enclosing a piston 137 provided with a piston rod 141 projecting through one end of the cylinder 135. The piston rod 1 may conveniently be provided with a suitable aperture in its outer end for engagement with a pin 139 depending from the sub-base 134 as shown in FIG. 4. Thus, suitable manipulation of the valve V15 will result in displacing the piston 137 within the cylinder 135 to move the combined mechanism 13% toward and away from the workpiece 28 as desired in order to permit traversal of the supporting means for the workpiece without interference with any portion of the combined mechanism 136;. In a fully automated system, the valve V15 illustrated as manually operated could of course be automatically actuated in proper coordinated relation to operation of automatic means for traversing the workpiece supporting means.

Thus the instant invention provides a compact integrated rnechanism incorporating in a single housing means for performing various necessary functions with respect to the portion of a workpiece being ground and control means to assure that these various functions are performed in the proper sequence and at the proper point in a grinding operation. In addition, the instant invention provides 12 means for coordinating the respective phases of a feeding cycle with the performance of various necessary functions with respect to the portion of a workpiece being ground.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth within the scope of the appended claims, it is to be understood that all matter hcreinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. in a grinding machine having a base, a transversely movable rotatable grinding wheel thereon; means including a traversable member on the base for presenting different portions of a workpiece to be ground opposite the grinding wheel; and a rotatable work support on the tra versable member including a pair of spaced aligned rotatable pot chucks supporting a workpiece to be ground; an adjustable housing slidably mounted on the base; and means to traverse aid housing toward and away from a workpiece; said housing supporting means to sense the presence of a workpiece in the grinding machine, means to axially position a workpiece relative to the grinding wheel combined with means to support the portion of a workpiece being ground on a common support movable relative to said housing in a first sense to actuate said means to axially position a workpiece and in a second sense to actuate an element of said means to support the portion or" a workpiece being ground, and means for gaging a workpiece arranged to be actuated with said scans to support the portion of a workpiece being ground.

2. An integrated mechanism for a machine tool comprising means to sense the presence of a workpiece therein, means initiated by said sensing means to automatically begin the machining cycle of the machine tool, means to axially position a workpiece relative to a cutting tool, means to support the portion of a workpiece being machined, and means to gage a workpiece operatively connected to control means including an adjustable timing mechanism actuated by said gaging means when a workpiece has been reduced to a predetermined size temporarily to interrupt the infeed of a cutting tool into a workpiece, means actuated by said timing mechanism at the end of the timing period to continue the infeed of a cutting tool, and control means actuated by said gaging means when a workpiece has been machined to the desired size to move a cutting tool to an inoperative position.

3. A combined compact unit for use with a grinding machine having a base, a transversely movable rotatable grinding wheel thereon, grindiny wheel feeding means and a rotatable work support on the base including a pair of spaced aligned rotatable pot chucks supporting a workpiece to be ground, said unit comprising means to sense the presence of a workpiece loaded into the said grinding machine and to initiate the grinding cycle of the grinding machine, means to axially position a workpiece having shouldered portions relative to the grinding wheel, means to support the portion of a workpiece being ground, means to gage a workpiece, means actuated by said means to gage a workpiece when a predetermined workpiece size is reached to interrupt and thereafter initiate resumption of infeeding movement of the grinding wheel at a reduced feeding rate, and means actuated by said means to gage a workpiece when a workpiece reaches the desired size positively to terminate the infeeding movement of the grinding wheel.

4. In a grinding machine having a base, a transversely movable rotatable grinding Wheel thereon, means including a traversable member on the base for presenting different portions of a workpiece to be ground opposite said grinding wheel, and a rotatable work support on the traversable member; an adjustable housing slidably mount- 13 ed on said base; means to traverse said housing to an inoperative position away from -'a workpiece when the traversable member is to be moved and to an operative position after the 'traversa'bl'e member has been moved; said housing supporting means to sense the presence of a workpiece in "the grinding machine, means to axially position a workpiecerelative to the grinding wheel, steadyrest in'ggr'oundto 'a'pr'edete'rmined dimension moved into enaga'ge'mehtwith a'workpi'e'ce concurrently Withsaid steady- "rest means.

'5. In a'mfachine tool having a base, a transversely movable rotatable cutting tool thereon, and a rotatable work supporting means on the base including a pair of spaced aligned rotatable work supports supporting a workpiece having spaced shouldered portions thereon, an integrated assembly mounted on the base comprising a housing, means to sense "the presence of a workpiece in the machine tool, means to axially "position the portion to be machined of a workpiece relative to the cutting tool,

means to'support the portion of a workpiece being machined including a pair of steadyrest members, one of said'steadyrest members being'combined with said axial positioning means, and the other one of said steadyrest members being pivotally mounted upon said housing,

means to gage and size aportion between the shouldered portions of a workpiece during the machining thereof, first actuating means for actuating said axial positioning means, second actuatingmeans to actuate said steadyrest means andsaid gaging and sizing means, a rotatable and axially movable first elongated member supporting said combined axial positioning means and one of said steadyrest members fixedly upon one end thereof, and an axially movable second elongated member acting on the other of said steadyrest members and said gaging and sizing means, said rotatable and axially movable first elongated member being selectively rotated by said first actuating means and held against rotation by said first actuating means during sequential axial displacement ofsaid first elongated memher by said second actuating means.

6. In a machine tool having a base, a transversely movable rotatable cutting tool thereon, and a rotatable work supporting assembly on the base including a pair of spaced aligned rotatable work supports supporting a workpiece having spaced shouldered portions and a cylindrical portion therebetween all to be machined, a combined unit mounted on the base comprising a housing, means actuated by the presence of a workpiece in the machine tool for initiating a machining cycle, means to axially position the portion to be machined of a workpiece'relative to the cutting tool, means to support the portion of a workpiece to be machined including a pair of steadyrest members, one of said steadyrest members combined with said axial positioning means, and the other one of the said steadyrest members pivotally mounted upon said housing, means to gage and size the portion to be ground of a workpiece during the machining thereof, first actuating means including a fiuid motor for operating said axial positioning means, second actuating means including a fluid motor for operating said steadyrest members and said gaging and sizing means, a rotatable and axially movable first elongated member supporting said combined steadyrest member and axial positioning means fixedly secured to one end thereof, and an axially movable second elongated member acting on the other of said steadyrest members and said gaging and sizing means, said first elongated member being rotated by said first actuating means and 14 held against rotation by said first actuating means during sequential axial displacement of said first elongated member along with said second elongated member by said second actuating means.

7. Apparatus as described in claim 6, wherein said combined axial positioning means and steadyrest member comprises an axial positioning means having a concave face shaped and disposed to be positioned substantially concentric of and spaced from the cylindrical portion to be machined of a workpiece when the axial positioning meansis disposed in its inoperative position, and a steadyrest member mounted centrally on the concave face of said axial positioning means and projecting therefrom toward the portion to be ground of a workpiece.

8. An integrated mechanism for a machine tool comprising a housing mounted upon a machine tool, means supported by said housing operable to axially position a workpiece relative to a cutting tool on a machine tool, and means supported by said housing operable to support the portion of a workpiece being machined on a machine tool, said integrated mechanism including an elongated supporting element mounted for both rotating and sliding movement, relative to said housing and having fixedly 'securedthereto at one end thereof said means to axially position a workpiece and an element of said means to support theportion of a workpiece being machined.

9. A mechanism for use on a machine tool comprising a housing mounted upon a machine tool, an elongated supporting element mounted within said housing for rotation and for sliding movement relative to said housing, means to axially position a workpiece relative to the cutting element of a machine tool including said elongated supporting element and positioning means fixedly secured to one end of said supporting element, work support means to support the portion of a workpiece being machined on a machine tool includingsaid elongated supporting element and a worksupport element fixedly secured to the same supporting element mounted within said houisng for rotation about its longitudinal axis and for sliding movement along its longitudinal axis, means to axially position a workpiece relative to the cutting element of a machine tool including said elongated supporting element and positioning means fixedly secured to one end of said supporting element concentric to the longitudinal axis of said supporting element and having opposed workpiece carnming surfaces, steadyrest means to support the portion of a workpiece being machined on a machine tool including said elongated supporting element and a steadyrest element fixedly secured to the same end of said supporting element concentrically of saidpositioning means, and differential actuating means sequentially operable first to rotate said supporting element to actuate and then retract saidpositioning means and then to movesaid supporting element slidably to actuate and then retract said steadyrest element.

11. An integrated mechanism for a machine tool comprising a housing mounted upon a. machine tool, means mounted upon said housing to sense the presence of a workpiece in a machine tool, work positioning means supported by said housing operable to axially position a workpiece relative to a cutting tool on a machine tool, work support means supported by said housing operable to support the portion of a workpiece being machined on a machine tool, and means supported by said housing and actuated with said work support means to gage the portion of a workpiece being machined, said integrated mechanism including an elongated supporting element with one end projecting from said housing selectively a sence 1 5 alternatively movable rotatably about its longitudinal axis and lengthwise of its longitudinal axis and having said work positioning means and an element of said work support means fixedly secured thereto at the end projecting from said housing with said element of said work support means disposed centrally of and projecting from said work positioning means.

12. Apparatus for a grinding machine arranged to grind a workpiece having spaced shouldered portions thereon to be positioned symmetrically relative to a rotatable grinding wheel for grinding away equal amounts from the respective shouldered portions during a grinding operation, said apparatus including an elongated supporting element sequentially movable rotatably about its longitudinal axis and movable lengthwise of its longitudinal axis, axial positioning means mounting on one end of said supporting element for rotation therewith about its longitudinal axis for precisely locating a workpiece axially of a grinding wheel, retractable steadyrest means for supporting the portion of a workpiece to be ground including a steadyrest element mounted upon said supporting element centrally of said axial positioning means for axial movement with said supporting element, workpiece gaging means, first actuating means operable with a second actuating means at rest to actuate said axial positioning means by rotating said supporting element, and second actuating means operable with said first actuating means at rest to actuate said steadyrest means and said gaging means concurrently including means to move said supporting element lengthwise of its longitudinal axis.

13. An integrated mechanism for a machine tool comprising a housing mounted upon a machine tool, an elongated supporting element mounted within said housing for rotation about its longitudinal axis and for sliding movement along its axis, means mounted upon said housing to sense the presence of a workpiece in a machine tool, positioning means to axially position a workpiece relative to a cutting element or" a machine tool including said elongated supporting element and positioning means having opposed workpiece camrning surfaces fixedly secured to one end of said supporting element, steadyrest means to support the portion of a workpiece being machined on a machine tool including said elongated supporting element and a steadyrest element fixedly secured to the same end of said supporting element centrally of said positioning means, workpiece gaging means mounted upon said housing, and actuating means for said positioning means and for said steadyrest means and said gaging means including differential actuating means sequentially operable first to rotate said supporting element to actuate and then retract said positioning means and then to move said sup- 1 3 porting element slidably to advance and then retract said steadyrest element as said steadyrest means and said gaging means are displaced concurrently by said actuating means.

=14. A mechanism for use with a grinding machine ha 'ing a base, a transversely movable rotatable grinding wheel thereon, grinding wheel feeding means, and a rotatable worl; support on the base for supporting a workpiece to be ground, said mechanism comprising a housing, means mounted on said housing actuated by the presence of a workpiece loaded into a grinding machine to initiate the grinding cycle of a grinding machine, supporting means to support the portion of a workpiece being ground mounted upon said housing for movement relative thereto toward and away from a workpiece, gage means for gaging a workpiece mounted upon said housing for movement relative thereto toward and away from a workpiece, actuating means mounted upon said housing operable to advance and retract said supporting means and said gage means in unison, and wheel feed control means actuated by said gage means during the grinding cycle operable in response to successive signals from said gage means as predetermined workpiece sizes are reached to modify and then to terminate the feeding movement of a grinding wheel toward a workpiece.

15. A combined compact unit for use with a grinding machine having a base, a transversely movable rotatable grinding wheel thereon, grinding wheel feeding means and a rotatable work support on the base including a pair of spaced aligned rotatable pot chucks supporting a workpiece to be ground, said unit comprising means actuated by the presence or" a workpiece loaded into the grinding machine to initiate the grinding cycle of a grinding machine, means to axially position a workpiece having shouldered portions spaced transversely relative to the grinding wheel, means to support the portion of a workpiece being ground, and means to gage a workpiece connected to wheel feed control means operable in response to signals from said means to gage a workpiece when predetermined workpiece sizes are reached to regulate and then terminate the feeding movement of a grinding wheel toward a workpiece.

References Cited in the file of this patent UNITED STATES PATENTS 2,521,979 Jagen Sept. 12, 1950 2,693,062 Silven et al Nov. 2, 1954 2,723,504 Alvord Nov. 15, 1955 2,756,551 Alvord July 31, 1956 2,899,778 Bricker et al. Aug. 18, 1959 

2. AN INTEGRATED MECHANISM FOR A MACHINE TOOL COMPRISING MEANS TO SENSE THE PRESENCE OF A WORKPIECE THEREIN, MEANS INITIATED BY SAID SENSING MEANS TO AUTOMATICALLY BEGIN THE MACHINING CYCLE OF THE MACHINE TOOL, MEANS TO AXIALLY POSITION A WORKPIECE RELATIVE TO A CUTTING TOOL, MEANS TO SUPPORT THE PORTION OF A WORKPIECE BEING MACHINED, AND MEANS TO GAGE A WORKPIECE OPERATIVELY CONNECTED TO CONTROL MEANS INCLUDING AN ADJUSTABLE TIMING MECHANISM ACTUATED BY SAID GAGING MEANS WHEN A WORKPIECE HAS BEEN REDUCED TO A PREDETERMINED SIZE TEMPORARILY TO INTERRUPT THE INFEED OF A CUTTING TOOL INTO A WORKPIECE, MEANS ACTUATED BY SAID TIMING MECHANISM AT THE END OF THE TIMING PERIOD TO CONTINUE THE INFEED OF A CUTTING TOOL, AND CONTROL MEANS ACTUATED BY SAID GAGING MEANS WHEN A WORKPIECE HAS BEEN MACHINED TO THE DESIRED SIZE TO MOVE A CUTTING TOOL TO AN INOPERATIVE POSITION. 